In the automotive arts, it is a well known practice to attach the roof panel to each of the left and right body side panels via a respective roof ditch. In this regard, a sealant or sealer tape is used to seal the overlapping metal edges of the roof and respective body side panels, wherein the roof ditch is thereupon covered by a cosmetic roof ditch molding. See, for example, U.S. Pat. Nos. 7,004,535 and 6,030,701.
A roof ditch and associated roof ditch molding of interest is utilized by General Motors Corporation of Detroit, Mich. with respect to its 2006 Chevrolet Impala, of which various aspects are exemplified at FIGS. 1 through 5.
As shown at FIG. 1, a roof ditch 10 runs longitudinally along each of the left and right joinders of the roof panel 12 with the left and right body side panels 14, 16. As best seen at FIGS. 2 and 3, the roof ditch 10 is configured as a slot, having at its floor the overlap of a roof edge 12a with a respective body panel edge (left body side panel edge 14a being shown by way of example in FIGS. 2 and 3). A sealer tape 18 is located at the floor to seal the overlap of the edges. A roof ditch molding 20 is placed into each roof ditch above the sealer tape 18 to provide a cosmetic match between the roof panel and the left and right body side panels.
The roof ditch moldings 20 are each composed of a plastic extruded central molding member 20a and a pair of separately plastic injection molded end caps 20b, 20c (see FIG. 1, as well as FIG. 4, whereat only end cap 20b is shown). The central molding member 20a has a T-shaped cross-section defined by a head 22 and a beam 24, having preferably a metal insert 25 for stiffening. The visible portion of the head 22a has a Class A finish which cosmetically matches the finish of the roof panel 12 and right and left body side panels 15, 16. At the lower extremity of the beam 24 is a pair of wings 26 which are periodically present along the length of the beam to provide securement by flexed conformance to the roof ditch at locations P1 and P2 (see FIG. 2). In order to prevent end peeling of the roof ditch molding from the roof ditch, each end portion of the beam is modified to remove the wings and provide thereat a plunger 28 which interferingly couples to a spring bracket 30 which is, itself, anchored in the roof ditch at the sealer tape 18 (see FIG. 3).
FIG. 5 is a block diagram 50 indicating the steps of manufacture of the prior art roof ditch molding 10.
At execution Block 52, the central molding member 20 is extruded, inclusive of the head 22, the beam 24 and the wings 26, wherein the wings may be composed of a more flexible material than the central molding member.
At execution Block 54, the wings are routered away at the end portions of both ends of the beam (see 24a in FIG. 4) and at selected periodic locations along the beam so that discrete sections of wings are present between the end portions.
At execution Block 56, a surface prep 32 (see FIG. 3) is applied to the beam 24 at the end portions, the end portions are then placed in an injection molding machine, and the plungers 28 are then formed as a plastic injection mold onto the beam.
Finally, at execution Block 58 each end cap 20d is separately injection molded onto the respective ends of the central molding member by placement of a section of each end portion of the central molding member into an injection molding machine (the result is shown best at FIG. 4).
While the roof ditch molding 20 serves its purpose quite well, there is difficulty encountered with respect to providing a seamless look to the Class A finish 22a of the head 22 and the Class A finish 20d of the end caps 20a, 20b, particularly in view of the line of interfacial demarcation 34 as between the extruded central molding member and the injection molded end caps. Further, while the injection molding of the plungers creates heat to the Class B side, this heat can cause untoward deformation of the Class A side of the head.
Accordingly, what remains needed in the art is some way to make a Class A finish seamlessly extending between the central molding member and the end caps of a roof ditch molding.